Spreader for insecticidal compositions and the like



Patented Sept. 22, 1925.

UNITED STATES PATENT OFFICE.

-HARRY B. GOODWIN, OF GRAND JUNCTION, COLORADO, ASSIG-NOR TO THE LATIMER GOODWI-N CHEMICAL COMPANY, OF GRAND JUNCTION, COLORADO, A CORPORATION OF COLORADO.

SPREADER FOR INSECTICIDAL COMPOSITIONS AND THE LIKE.

No Drawing.

To all whom it may concern:

contemplated applying that principle, so as to distinguish it from other inventions.

With the almost universal adoption of dry powdered .lead arsenate as a spray material for the control of leaf-eating insects, the manufacture of this material has become practically standardized as regards its chemical composition. With no further improvement to be looked for on the chemical side, attention has been directed toward the improvement of the water-lead arsenate .spray mixture so as to make t a more efficient agent. Work in this field has followed 1. two lines of development, the firstv being an effort to improve-the physical properties of the 'solid'lead arsenate, and the second being an efl'ort'to improve the liquid or water phase'of the system.

Quite early in the manufacture of 'powdered .lead arsenate it was noticed that the fine particles tended to cohere, forming groups or flakes when the material was suspended in water. These flakes are objecftionable for two reasons. In the first place,

Vember 18, 1919, the addition of a colloid,-

'a cluster of particles will not cover as much surface as the; individual particles uniformly dispersed through the liquid, and second, the clusters in suspension behave like solid particles of relatively large size in that they settle out of the water rapidly.

Asdisclosed in U. S. Letters Patent No. 1,322,008, granted to'me under date ofNo- Specifically a relatively chemically inert colloid of organic origin, of whichtanmn is a preferred example, to'dry lead arsenate will overcome this tendency to cluster and produce a spray mixture in which the particles are practically as finely divided as at the time of their formation in the precipitating tank. The use of such a deflocculator, in other words, gives a spray mixture in which the lead arsenate particles are evenly dispersed and they remainin sus- Application filed December 6, 1923. Serial No. 679,000.

pension for 'a much longer time. Such (is-- flocculator requires to be used in very small amounts only, as little as lb. of tannin to 100 lbs. of lead arsenate producing satisfactory results. Other deflocculating agents that.may be used With satisfactory results are gum arabic, glueor gelatin and alkali metal salts of casein, specifically sodium caseiuate.

The efforts to make the water a more effective agent have been along the line of reducing the surface tension of the liquid.

The fruit and leaves of plants acquire a wax-like covering as the season advances and when a water-lead arsenate spray is applied in the usual manner, the fog of spray tends to draw together in drops instead of spreading out in a thin la, er.

Materials added for the purpose 0 thus increasmg the Wetting and covering power of the spray solution have been appropriately termed Spreaders by Prof. A. L.

Lovett who has investigated a number of substances inz regard to their desirabilityfor this purpose, as reported in Oregon Ag-- ricultural College Experiment Station Bulletin 169. The materials named in the fore going bulletin as showing value as spreaders in the poison spray solution given in order of their merit, based on'compatibility, efficiency, availability, cost and ease ofpreparation, are :caseinate, %lue, gelatin, soap bark and oil emulsions. ince the publication of Dr. Lovetts work (1920), there has grown up a very considerable business in the manufacture and sale'of lime casein mixtures to be added to spray tanks. The

quantities in which this material is soldis.

evidence that fruit growers believe they are obtaining better results through its use.

In order to be wholly satisfactory, a spreader should possess the following properties, viz, (1) it must not affect the spray material, fruit or foliage injurlously; (2)

it should be effective in small quantit1es;'

(3) it should be salable in dry form; (4) is should be quickly and completely soluble in cold water; and it should be a chemical compound. If t e above be taken as the properties to' be possessed by a perfect spreader, then all of the materials so far suggested for this use have one or more counts against them. As a result, however,

of prolonged and careful investigation, I

have found that certain substances belonging to the class of so-called gum-resins appear to be best suited for this purpose. As examples of such gum-resins, olibanum, myrrh, mastic and gamboge may be mentioned, but the last named appears to be satisfactory to a most unusual degree. The

foregoing materials and particularly gamboge will now be set forth with some particularity, it being understood, however, both as to the ingredients employed in my improved spreading material and as to the method of making and using same, that changes may be made therein without departing from the spirit of the invention.

Gamboge, also written gambooge, is the inspissated juice of various species of the guttiferous genus Garcinia, the gamboge of commerce being mainly derived from G. Hanburyi which is a native of Siam, Cambodia and Cochin, China. It is a gum-resin product, the only uses of which heretofore have been in medicine where it acts as a drastic purgative and as a pigment in watercolor painting for the production of transparent yellows verging on brown in deep masses. For use as a spreader with water mixtures of calcium arsenate and other insecticidal compositions that have sufiicient alkalinity to disolve gamboge, the commercial product may be directly employed, but preferably I convert the same into the form of an alkali metal salt, specifically sodium gamboge. As an example of such conversion, I add to 100 lbs. of gamboge 12 lbs. of sodium hydrate, 3.2 ounces of potassium dichromate, and enough water to make a stiff paste. By means of suitable apparatus, which need not be described, the materials are kneaded or rubbed into a uniform paste without lumps, no heat being required. Such paste is then dried in warm air at about 130 degrees F., but any standard method for drying materials of similar nature may be employed. The resultant dry cake is then pulverized in a suitable mill,

the product being a finely divided powder varying in color from yellow to light brown.

Instead of adding only enough water to form a paste, a greater quantity of water may be used so that the ingredients are all in solution and this solution can then be boiled untilthe excess water is removed and a paste formed,=the final water in the paste then 'being removed by drying at a. lower temperature as before. Other oxidizing agents than potassium dichromate' may be used, such for example as sodium dichromate,

hydrogen peroxide, sodium peroxide, sodium nitrate, sodium perchlorate, potassium permanganate, the choice being determined by the market price, permanency and ease of handling. The dichromate is preferable because it is a dry salt that'does not lose its ox1d1z1ng power under normal conditions;

reported in the Journal of the Optical Society of America and Review of Scientific Instruments, vol. 6, No. 7,,Sept. 1922. A parafiin oil having a specific gravity of 0.885 was used as a surface layer in all of the experiments and in preparing the substances for examination, the following procedure was followed, viz, 0.3 grams of such substance were dissolved in distilled water and diluted to 250 co. in a graduated flask, this representing 2 lbs. of spreader in 200 gallons of water or 50 per cent of the arsenate of lead power on the assumption that 4 lbs. is the usual amount of the latter added to a 200 gallon tank. After mixing, half of this spreader solution was used to obtain the result in an appropriately designated column of the subjoined tabulated statement. The other half was diluted to 250 co. .in the same flask, thus giving the equivalent of 1 lb. of spreader to 200 gallons or 25 per cent of lead arsenate when used in the usual spray strength. The results in this case, as also in the case where the spreader is employed in an amount equivalent to 5 per cent and in an amount equivalent to of 1 per cent of the lead arsenate, respectively. are likewise shown in the table which follows.

For the purpose of comparison, corresponding tests with other substances heretofore used or suggest-ed for use as spreaders are tabulated along with the results obtained with sodium gambogeflt being noted that the interfacial tension ,of the oil anddistilled water employed in these tests at room temperature was 31 dynes.

I. lnterfacz'al tension ofi various Spreaders (in rig hes per mm).

Amount of spreader in 210 gallons water stated amounts of tannin and gamboge were added to 250 cc. of water, and the per cent of particles of such arsenate determined in the upper 132 cc. and the lower 118 00;, respectively, of the liquid was determined after standing five minutes, viz

II. Suspensioe power of tanm n and gamboge. v

Bottom layer Top layer Per cent Per cent 1 gram lead arsenate 10-25 Neither tannin nor gamboge, or the combination of the two, appears to-have any unfavorable chemical reaction on lead arse nate, as indicated by the following tests III. Amount of soluble amen/i0.

Percent. Lead arsenate 0.45 Ditto plus gamboge ....c 0.45 Ditto plus tannin 0.34 .Ditto plus tannin and gamboge 0.34

Other deflocculators may be found more desirable than tannin for use with my im-.

' gallons of water.

i tests of a spray mixture proved spreader, but assuming tannin to be used for the purpose, the complete mixture for commercial purposes will consist of 0.82 ounces of sodium gamboge, prepared as hereinbefore described, together with 0.32 ounces of tannin, this being the proper amount for use with a spray mixture consisting of 4 lbs. of lead arsenate in 200 The deflocculator-spreader mixture may be added to the powdered lead arsenate at the factory or it may be sold to the consumer for addition to the spray mixture in the .field. Actual .field with such-deflocculater-spreader mixture added show that. the surfaces of apples, for example, when sprayed in the ordinary way, are uniformly coated with the lead arsenatev It should.

furthermore be noted that gamboge-tannin in the amount of 0.04 lb. to 200 gallons shows no alkalinity.

- The chemical composition of gamboge, so far as I am aware, is unknown. I have found, however, that it includes constitu ents that are respectively soluble and insoluble in water. If the-raw gum of commerce be boilgd'with water, no alkali being used, a yellow opalescent'solution of certain of the constituents of. the gum is formed from which the insoluble constituents may be separated by'decantation. A test of the 39 45 'Ditto plus 6 of 1% tannin 50. 50 49. 50- Ditto plus of 1% gamboge 26.15 73. 85 7 Ditto plus of 1% tannin and of 1% gamboge 49. 25 50.

" tinctly claim. as my invention compositions merely.

the form or construction, 'ments stated by any of the following claims employed,

solution thus obtained does not indicate that such soluble constituents are particularly effective in reducing the-surface tension of the watery vehicle. However, if sodium hydroxide in approximately the proportion indicated above for use with the original gum be added to such solution, very satisfactory spreading action is secured. The insoluble constituents if similarly reacted on with sodium hydroxide when used in an amount approxi1nati'ng.from '5 to 50 per cent of the arsenate of lead powder, have a marked spreading efi'ect. In the absence of a better general term I have used herein the name gamboge to designate inclusively the gum commercially known under this name, the constituents of such gum or such-'- alkali metal salt thereof as will have the spreading action described above.

In conclusion I should state that while I have hereinbefore referred to the use of myimproved spreader, specifically sodium gamboge, with insecticidal spray mixtures wherein lead arsenate is used as the insecticide proper, the effect of such spreader in reducing the surface tension of the liquid vehicle is not spray composition nor to use with spray On the contrary, there are many other industrial applications which need not here be enumerated for the use of such a compound.

The other gum resins hereinbefore named are prepared for use as spreaders in substantially the same manner as gamboge, to which the foregoing detail description particularly relates. I have found, however, that the limited to this particular alkaline." derivatives of such other gum resins are equal in effect to the gamboge derivatives only when used in larger amounts. For example, two pounds of the sodium compound of olibanum' in 200 .gal-

ions of water will have the same efiect as two pounds of sodium gamboge (see Table I ante), but two-tenths of a pound of. such first named compound will not be nearly as effective as the corresponding smaller amount of sodium gamboge.

Other forms may be employed embodying the features of-my invention instead of the one here explained, change provided-the eleor the equivalent of such stated elements-be whether produced by my prebeing made in ferred method or by others embodying steps equivalent to those stated in the following claims. 9 a y I therefor particularly po nt out and dis '1. The method of reducing the surface tension of a watery vehicle in various indus trial applications, thereto a gum-re'sln derivative,

which consists in adding tension of a Water vehicle in various indus- 2. The method of reducing the surface tension of a Watery vehicle in various industrial applications, which consists in adding thereto an alkali metal derivative of a gumresin, substantially as described.

3. The method of reducing the surface trial applications, which consists in adding thereto a derivative of gamboge.

4. The method of .reducing the surface tension of a Watery vehicle in various industrial applications,'which consists in adding {hereto an alkali metal derivative of gamioge.

5. The method of reducing the surface tension of a Watery vehicle in various industrial applications, which consists in' adding sodium gamboge thereto.

6. The method of increasing the spreading quality of an insecticidal spray mixture of the character described, which consists in adding gamboge thereto.

7. The method of increasing the spreading quality of an insecticidal spray mixture of the character described,'which consists in adding thereto an alkali metal salt of gamboge.

8. The method of increasing the spreading quality o f an insecticidal spray mixture of the character described, which consists in adding sodium gamboge thereto.

9. A composition of matter for insecticidal use comprising an insoluble metallic arsenate and gum-resin derivative.

10. A' composition of matter for insecticidal use comprising an insoluble .metallic arsenate and gamboge.

11'. A composition of matter for insecticidal use comprising lead arsenate and a relatively smaller amount of gamboge.

12. A composition of matter for insectici- HARRY B. GOODWIN. 

